Semi-rigid framework for a plate haptic intraocular lens

ABSTRACT

A plate haptic for an intraocular lens. The plate haptic has a haptic body that is substantially rigid in a longitudinal direction and substantially flexible in a transverse direction. A chassis is integral to the haptic body. The chassis causes the haptic body to be substantially more rigid in a longitudinal direction than in a transverse direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/155,327, filed Jun. 7, 2011, which claims the benefit of the filingof U.S. Provisional Patent Application No. 61/398,107 filed Jun. 21,2010; U.S. Provisional Patent Application No. 61/398,098 filed Jun. 21,2010; U.S. Provisional Patent Application No. 61/398,115, filed Jun. 21,2010; and U.S. Provisional Patent Application No. 61/398,099, filed Jun.21, 2010, the contents and disclosure of which are fully incorporatedherein by reference.

This application is related to U.S. Non-Provisional patent applicationSer. No. 13/017,189, filed Feb. 14, 2011; and U.S. Non-Provisionalpatent application Ser. No. 13/092,359, filed Apr. 22, 2011; and U.S.Non-Provisional patent application Ser. No. 13/111,599, filed May 19,2011, the contents and disclosure of which are fully incorporated hereinby reference.

BACKGROUND OF THE INVENTION

Accommodating Intraocular Lenses were developed in the early 1900's andhave been sold in Europe for the last ten years and later in the U.S.They function by means of forward movement of the optic uponconstriction of the ciliary muscle which increases the pressure in theposterior part of the eye with a simultaneous decrease in pressure inthe front part of the eye pressure. The reverse pressure changes takeplace upon relaxation of the ciliary muscle, which results in thebackwards movement of the lens for distance vision. The forward movementof the lens optic enables the patient implanted with the lens toautomatically change their vision from distance to see at intermediateand near.

The currently marketed accommodating plate haptic intraocular lensesprovide excellent distance and intermediate vision but sometimes requireweak, +1.00, reading glasses for prolonged reading, for seeing smallprint, or reading in dim lighting conditions. The embodiments relatingto the present invention presented herein are designed to substantiallyreduce the need for any reading glasses.

It is important for intraocular lenses to have a consistent locationalong the axis of the eye to provide good uncorrected distance visionand to center in the middle of the vertical meridian of the eye. Withoutexcellent uncorrected distance vision there is no point in implanting anaccommodating lens whose function is to enable patients to be withoutglasses.

The word “haptic” has been used to describe an attachment to intraocularlenses. The original intraocular lens consisted of a single optic. Thesesingle optic lenses, without any attachments, were first implanted inLondon by Harold Ridley in 1949. These lenses frequently de-centered andit was discovered that there was a need to center and fixate the lensoptic in the vertical meridian of the eye. The first attachments to theoptic were called “haptics”. They consisted of multiple flexible loopsof various designs, J loops, C loops, closed loops and flexible radialarms. Later, these loops which became commonly referred to as “haptics”were replaced in some lens designs with plates, called “plate haptics”.Current plate haptic designs reduces the incidence of post-operativecomplications of cataract surgery, including retinal detachment andcystoid macular edema. Also, because of the more consistent location ofthe lens along the axis of the eye, the uncorrected post-operativevisual acuities are superior to those of loop haptics.

During constriction of the circular ciliary muscle in an eye fitted witha plate haptic accommodating intraocular lens, the diameter of theciliary muscle decreases and the muscle compresses the distal ends ofthe plate haptics, moving them centrally. Because uni-planar platehaptics tend to vault posteriorly when placed into the capsular bag, thecentral movement of the plate haptics causes their proximal end attachedto the optic to move posteriorly and centrally. This posterior movementof the plates increases the vitreous cavity pressure behind the lens andits optic and simultaneously decreases the vitreous cavity pressure inthe anterior chamber of the eye and accommodates for near vision.

The current accommodating intraocular lenses utilize an oblong lens bodydesign having flexible plate haptics connected to the lens optics by asingle transverse hinge across the plate haptic. This promotesaccommodation by allowing the optic to move forwards and backwardsrelative to the outer, or distal, ends of the plates. Such accommodatinglenses are found in U.S. Pat. No. 5,476,514 and U.S. Pat. No. 5,496,366,both to Cumming, the disclosures of which are herein incorporated byreference. However, such designs do not permit adequate movement of theoptic to a change in vitreous cavity pressure to allow many patients toread comfortably at near without glasses.

Current plate haptics are constructed of silicone, hydrogel or acrylicand are generally flexible. Due to this flexibility, current platehaptics tend to slightly buckle or deform when longitudinally compressedby the constriction of the ciliary muscle. This buckling reduces thepossible pressure applicable by the plates on the vitreous cavity withconstriction of the ciliary muscle.

Furthermore, when the accommodating lens plate haptic is fibrosed intothe capsular bag of an eye after cataract surgery, sometimes severalweeks or months following the surgery, a complication can occur. Thelens can deform to a “Z” dislocated shape. This occurs when there islittle sandwiching of the distal tip of the plate haptics between theremaining anterior and the posterior walls of the capsular bag.

SUMMARY OF THE INVENTION

A plate haptic accommodating intraocular lens design according to anembodiment of the present invention is described that overcomes thedeficiencies of present designs noted above.

A flat, longitudinal accommodating intraocular lens is provided, havingdistinct separate plate haptics that are rigid longitudinally, butflexible transversely, and that extend to partially surround the optic.The transverse flexibility of the plate haptics permits theaccommodating intraocular lens to be folded longitudinally and insertedinto the eye via a small incision therein. The longitudinal rigidity ofthe plate haptics inhibits the buckling or deforming of the plate hapticduring accommodation. Thus, the plate haptics may exert more pressure onthe vitreous cavity, thereby increasing the forward movement of the lensoptic.

The flat plate haptics may have a groove or hinge portion across thewidth of its proximal ends adjacent to the optic. This hinge may beweakened by comprising at least two separate spaced apart narrow hingeson each edge of the plate haptics, thereby, reducing the overall lengthof the hinge. This plural strap design stabilizes the lens optic whilereducing the resistance of the optic to a change in vitreous cavitypressure, thereby, allowing more movement of the optic along the axis ofthe eye. Further stabilization is achieved by making the haptics aswide, or wider, than the optic and extending the lateral proximal endsof the plate haptics to partially surround the optic. The plate hapticsmay be made rigid longitudinally by incorporating into the length of thehaptics a rigid frame structure.

Thus, an accommodating lens according to the present invention maystabilize the solid, single, flexible lens optic, prevent tilt, providemore movement of the optic for better near vision and center and fixatethe lens in the capsular bag with finger-like flexible loops at thedistal ends of the plates. This accommodating lens improves near visionby reducing the resistance to pressure changes on the optic withcontraction and relaxation of the ciliary muscle and by furtherincreasing the vitreous cavity pressure by means of the lateral platehaptic extensions, which with accommodation and constriction of theciliary muscle are forced posteriorly such that their proximal ends tothen lie posterior to the optic.

Other features and advantages of the present invention will becomeapparent from the following more detailed description, taken inconjunction with the accompanying drawings, which illustrate, by way ofexample, the principles of the presently described apparatus and methodof its use.

BRIEF DESCRIPTION OF THE DRAWINGS

Illustrated in the accompanying drawing(s) is at least one of the bestmode embodiments of the present invention. In such drawing(s):

FIGS. 1-2 illustrate top views of a semi-rigid framework for a platehaptic accommodating intraocular lens according to an embodiment of thepresent invention;

FIG. 3 illustrates a side view of a plate haptic according to anembodiment of the present invention;

FIG. 4A-4C illustrates top views of exemplary plate haptic accommodatingintraocular lens according to various embodiment of the presentinvention;

FIG. 5A-5G illustrates top views of exemplary semi-rigid framework forplate haptics according to an embodiment of the present invention;

FIG. 6 illustrates a plate haptic accommodating intraocular lensaccording to an embodiment of the present invention; and

FIG. 7 illustrates a plate haptic accommodating intraocular lensaccording to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The above described drawing figures illustrate the described inventionand method of use in at least one of its preferred, best modeembodiment, which is further defined in detail in the followingdescription. Those having ordinary skill in the art may be able to makealterations and modifications to what is described herein withoutdeparting from its spirit and scope. Therefore, it should be understoodthat what is illustrated is set forth only for the purposes of exampleand should not be taken as a limitation on the scope of the presentapparatus and its method of use.

FIG. 1 illustrates an accommodating intraocular lens 10. Theaccommodating intraocular lens 10 comprises: a plurality of platehaptics 200 disposed on opposing ends of a lens optic 100. The platehaptics 200 are flexibly coupled to the lens optic 100 at a hingeportion 300.

Each plate haptic 200 comprises: a haptic body 210; a chassis 220integral to the haptic body 210; a centration member 240; a proximalportion 250; a distal portion 260; and opposing lateral portions 270. Insome embodiments, the width of the plate haptic 200 may be between 4.0and 6.0 mm, and the thickness of the plate haptic may be between 0.15and 0.75 mm.

The chassis 220 is integral to the haptic body 210 and may besubstantially more rigid in a longitudinal direction than in atransverse direction and may cause the plate haptic 200 to besubstantially rigid in a longitudinal direction and substantiallyflexible in a transverse direction. The chassis 220 may be separate fromthe haptic body 210, or may be unitary therewith. In at least oneembodiment, the haptic body 210 is made of a first material selectedfrom silicone, acrylic, hydro gels, or other similar material, and thechassis 220 is made of a second material selected from polyimide,prolene, PMMA, titanium, and other similar material. In at least oneother embodiment, the haptic body 210 is made of the first material andthe chassis 220 is a thickened portion of the haptic body. Thus, thehaptic body 210 may be substantially rigid in a longitudinal directionand substantially flexible in a transverse direction. The substantiallyflexible nature of the plate haptic 200 in the lateral direction permitsfolding the intraocular lens in the lateral direction so that it may beinserted into the eye through a small incision. However, thesubstantially rigid nature of the plate haptic 200 in the longitudinaldirection ensures that when the ciliary muscle exerts radial pressure onthe distal portion 260 during accommodation, the plate haptic 200 willmove centrally and posteriorly towards the optic 100 without bending orbuckling. Thus, a greater response to vitreous pressure change isachieved.

The distal portion 260 of the plate haptic 200 comprises a distal flange262 extending distally and laterally therefrom, the distal flangecomprising opposing lateral appendages 264 operable to engage thecapsular bag. These lateral appendages 264 may be substantiallytriangular in shape, but other shapes are also contemplated. As shown inFIG. 3, the distal flange is preferably thinner than the haptic bodyfrom which it extends. On insertion into the eye, the distal flange 262increases the contact area and provides additional fixation and supportfor the lens within the capsular bag.

The centration member 240 is integral to the distal portion 260 andextends therefrom. The centration member 240 comprises: a base 242integral to the haptic body 210 and at least one loop 244 extending fromthe base 242 beyond the haptic body 210 to engage a capsular bag. Asshown in FIG. 2, the centration member 240 may comprise opposing loops244 extending from the base 242 beyond the lateral sides 270 of theplate haptic 200. However, as shown in FIG. 5G, the centration member240 may comprise a single loop 244 extending beyond the distal portion260 at a location substantially nearer to one lateral side 270, towardsthe other lateral side 270. Additionally, as shown in FIG. 4A, thecentration member 240 may comprise a single loop 244 extending beyondone lateral side 270 of the plate haptic 200. In at least oneembodiment, the centration member 240 is integral to the chassis 220. Itis important to note that each plate haptic 200 may comprise a differentcentration member 240, or none at all. In one embodiment, the length ofthe accommodating intraocular lens without the centration member 240 is10.5 to 11.0 mm, while the length of the accommodating intraocular lenswith the centration member 240 is 11.5 to 12.5 mm. The flexible loops244 are preferably compressible centrally to fix and center theaccommodating intraocular lens within the capsular while minimizingtilt.

The plate haptic 200 may further comprise a plurality of opposing tabs212, or paddles, each tab 212, or paddle, formed by the intersection ofthe proximal portion 250 and an associated lateral side 270. Each tab212 may comprise at least one of: the haptic body 210 and the chassis220. In some embodiments, the tabs 212 are laterally divergent. As shownin FIG. 1, the tabs 212 may comprise the haptic body 210 and the chassis220 integral thereto. However, as shown in FIG. 5B, the tabs 212 maycomprise a chassis frame portion 222 extending beyond the haptic body210. The tabs 212 preferably extend from the haptic body 210 topartially surround the optic 100 in combination with the proximalportion 250 of the haptic body 210. In at least one preferredembodiment, the tabs 212 in combination with the proximal portion 250substantially occupy at least one-quarter of an optic periphery 110.Such wide tab construction offers increased stabilization of the opticand the plate.

The hinge portion 300 flexibly couples each plate haptic 200 to the lensoptic 100. As shown in FIG. 1, at least one strap 310 connects theproximal portion 250 of the plate haptic 200 to the periphery 110 of thelens optic 100. In one embodiment, the strap 310 may be 0.5 to 4.0 mm inwidth. The strap 310 is preferably flexible and/or stretchable orelastic such that it may respond to an increase in vitreous pressurechanges that may cause central and posterior movement of the platehaptics 200, thus permitting the optic 100 to move forward along theaxis of the eye. The strap may comprise a first surface and a secondsurface in opposition thereto. The strap may further comprise at leastone groove 320 traversing at least one of the first or second surfaces.The groove 320 preferably traverses the strap 310 parallel or tangentialto at least one of the proximal portion 250 or the optic periphery 110.The groove 320 further weakens the straps 310 resistance to vitreouspressure changes and permits greater accommodation. As shown in FIG. 5G,the hinge portion 300 may comprise at least two straps 310 that arelaterally spaced apart from each other, equidistant from a longitudinalaxis of the intraocular lens, such that the separation of straps 310ensures the transferred pressure is uniform. The hinge portion 300 mayhave a thickness that is half the thickness of the plate haptic 200, orpreferably a thickness of 0.10 to 0.30 mm. Preferably, the strap 310 isapproximately 1 to 1.5 mm long and may be thinner than the haptic body210.

FIG. 5 illustrates the chassis 220 according to various embodiments. Thechassis 220 may comprise a plurality of integral frame members 222 thatare spaced apart from each other so as to form a plurality of apertures224 therebetween, the apertures comprising the haptic body 210.

As shown in FIG. 5A, the chassis 220 may principally comprise aplurality of lateral frame members 222 a criss-crossing a plurality oflongitudinal frame members 222 b. Specifically, as shown in FIG. 5A, theframe members 222 a,b may be disposed so as to resemble the letter “E”and its mirror image about the longitudinal axis of the intraocularlens. Additional frame members 222 a,b may extend diagonally tointersect the centration member 240 at the base 242. As seen in FIG. 5A,the centration member 240 and the chassis 220 may comprise a unitarystructure.

As shown in FIG. 5B, the chassis 220 may principally comprise aplurality of longitudinal frame members 222 b disposed substantiallyparallel to each other and symmetrical about the longitudinal axis ofthe intraocular lens. Specifically, as shown in FIG. 5B, the framemembers 222 may be disposed so as to resemble the Greek letter “n”.Additional frame members 220 may extend longitudinally downward from thecrossing lateral frame member 222 a which may form the base 242 of thecentration member 240. As seen in FIG. 5B, the centration member 240 andthe chassis 220 may comprise a unitary structure. Additionally, as seenin FIG. 5B, the chassis 220 may form the tabs 212 via frame members 222extending beyond the haptic body 210.

As shown in FIGS. 5C and 5D, the chassis 220 may principally comprise aplurality of elliptical frame members 222 c symmetrically spaced fromeach other about the longitudinal axis of the intraocular lens.Specifically, as shown in FIGS. 5C and 5D, the frame members 222 may beintegral to the base 242 of the centration member 240. As seen in FIGS.5C and 5D, the centration member 240 and the chassis 220 may comprise aunitary structure. Additional frame members 222 may extend to connectthe substantially elliptical frame members 222 c or to provide furtherstructural support.

As shown in FIG. 5E, the chassis 220 may principally comprise aplurality of cross-diagonally disposed and intersecting frame members222 d. Specifically, as shown in FIG. 5E, the frame members 222 d may bedisposed so as to resemble the letter “x” and it's mirror image aboutthe longitudinal axis of the intraocular lens. Additional frame members220 may extend from the frame members 222 d to join them. As shown inFIG. 5E, the intersection of the frame members 222 d may form the base242 of the centration member 240. As seen in FIG. 5E, the centrationmember 240 and the chassis 220 may comprise a unitary structure.

As shown in FIG. 5F, the chassis 220 may principally comprise aplurality of longitudinal frame members 222 b disposed substantiallyparallel to each other. Specifically, as shown in FIG. 5F, the framemembers 222 may be disposed so as to resemble the letter “h” and it'smirror image about the longitudinal axis of the intraocular lens. Asseen in FIG. 5F, the centration member 240 and the chassis 220 maycomprise separate structures. Additionally, the chassis 220 itself maycomprise a multi-piece structure, or in other words, the chassis 220 maycomprise multiple chassis 220.

As shown in FIG. 5G, the chassis 220 may principally comprise aplurality of longitudinal frame members 222 b disposed substantiallyparallel to each other and intersected at either ends by lateral framemembers 222 a. Specifically, as shown in FIG. 5G, the frame members 222may be disposed so that a plurality of frame members 222 are displacedequidistant from the longitudinal axis of the intraocular lens and asingle frame member 222 is substantially coincident with thelongitudinal axis. Additional frame members 222 may extendlongitudinally downward from a crossing lateral frame member 222 a whichmay form the base 242 of the centration member 240. As seen in FIG. 5G,the centration member 240 and the chassis 220 may comprise a unitarystructure. Additionally, as seen in FIG. 5G, the chassis 220 may formthe tabs 212 via frame members 222 extending beyond the haptic body 210.

As shown in FIG. 4B, the lens optic 100 may have a periphery 110 thatextends laterally beyond the lateral sides 270 of the plate haptic 200.However, as shown in FIG. 4C, the lateral sides may extend laterallybeyond the periphery 110, and as shown in FIG. 4C, the lateral sides 270may be tangential to the periphery 110. The lens optic 100 may be madeof a flexible optical material such as silicone, acrylic, hydrogels, orother similar material, and is substantially flexible so as to enablefolding and insertion into an eye. Furthermore, the lens optic 100 ispreferably shaped so as to be biconvex, refractive, diffractive,plano-convex, Fresnel, spheric, aspheric, toric or multifocal.

In application, the accommodating intraocular lens is folded laterallyso as to enable insertion through a small incision into the eye. Thesubstantially flexible nature of the plate haptic 200 permits thisfolding. Once in the eye, the accommodating intraocular lens unfolds andis secured within the capsular bag. During accommodation the ciliarymuscle exerts radial pressure on the ends of the haptics 200, movingthem centrally and posteriorly towards the optic 100. Because it issubstantially longitudinally rigid, the plate haptic 200 resists bendingto the radial force exerted by the ciliary muscle. However, thestretchable hinge portion 300 is less resistant to the pressure from thevitreous cavity, and therefore stretches and flexes on application ofthe pressure. The separation of straps 310 ensures the transferredpressure is uniform, while the addition of the grooves 320 furtherweakens the straps 310 resistance to flexion/stretching. Thus, with theincrease in vitreous cavity pressure, the optic 100 is pushed forwardalong the axis of the eye, the optic 100 moving forward relative to boththe proximal 250 and distal portions 260 of the plate haptics 200,resulting in superior accommodation.

The enablements described in detail above are considered novel over theprior art of record and are considered critical to the operation of atleast one aspect of the invention and to the achievement of the abovedescribed objectives. The words used in this specification to describethe instant embodiments are to be understood not only in the sense oftheir commonly defined meanings, but to include by special definition inthis specification: structure, material or acts beyond the scope of thecommonly defined meanings. Thus if an element can be understood in thecontext of this specification as including more than one meaning, thenits use must be understood as being generic to all possible meaningssupported by the specification and by the word or words describing theelement.

The definitions of the words or drawing elements described herein aremeant to include not only the combination of elements which areliterally set forth, but all equivalent structure, material or acts forperforming substantially the same function in substantially the same wayto obtain substantially the same result. In this sense it is thereforecontemplated that an equivalent substitution of two or more elements maybe made for anyone of the elements described and its various embodimentsor that a single element may be substituted for two or more elements ina claim.

Changes from the claimed subject matter as viewed by a person withordinary skill in the art, now known or later devised, are expresslycontemplated as being equivalents within the scope intended and itsvarious embodiments. Therefore, obvious substitutions now or later knownto one with ordinary skill in the art are defined to be within the scopeof the defined elements. This disclosure is thus meant to be understoodto include what is specifically illustrated and described above, what isconceptually equivalent, what can be obviously substituted, and alsowhat incorporates the essential ideas.

The scope of this description is to be interpreted only in conjunctionwith the appended claims and it is made clear, here, that the namedinventor believes that the claimed subject matter is what is intended tobe patented.

What is claimed is:
 1. An intraocular lens comprising: an optic; and ahaptic comprising: a haptic body, the haptic body comprising a proximaledge, a distal edge, and opposing lateral sides therebetween, theproximal edge being closer to the optic than the distal edge, the hapticbody further comprising a pair of opposing paddles extending aroundopposite sides of the optic, each paddle formed by a portion of theproximal edge and one of said lateral sides of the haptic body, aproximal portion of each paddle being spaced apart from the optic, atransverse width measured between portions of the opposing lateral sidesforming the pair of paddles is greater than a transverse diameter of theoptic, the pair of paddles and the proximal edge of the haptic bodysurrounding at least one-quarter of an optic periphery; and a single,monolithic chassis at least partially internal to the haptic body, thechassis comprising a first portion extending into one of the pair ofopposing paddles and a second portion extending into the other of thepair of opposing paddles, the first portion and the second portionseparated by an open space and a transverse member defining a boundaryof the open space, such that the chassis is more rigid in a longitudinaldirection than in a transverse direction.
 2. The intraocular lens ofclaim 1, wherein the haptic is substantially rigid in the longitudinaldirection to resist deformation by the action of the ciliary muscle. 3.The intraocular lens of claim 1, wherein the haptic is a plate haptic.4. The intraocular lens of claim 1, wherein the haptic comprises acurved, open loop.
 5. The intraocular lens of claim 1, wherein thehaptic comprises one or more closed loops providing an enclosed openarea within.
 6. The intraocular lens of claim 1, wherein the haptic bodycomprises a flexible material and the chassis comprises a rigidmaterial.
 7. The intraocular lens of claim 1, wherein the haptic andoptic comprise a same material.
 8. The intraocular lens of claim 7,wherein the same material is acrylic.
 9. The intraocular lens of claim1, wherein the haptic comprises: a first material selected from a groupconsisting of silicone and polyimide, and acrylic; and a second materialselected from a group consisting of polyimide, titanium, nylon, andprolene.
 10. The intraocular lens of claim 1, wherein the haptic isconnected to the optic by a small extension of the optic.
 11. Theintraocular lens of claim 1, wherein a junction between the haptic andthe optic is configured to be distorted.
 12. The intraocular lens ofclaim 11, wherein the junction is configured to be distorted bystretching.
 13. The intraocular lens of claim 11, wherein the junctionis configured to be distorted by flexing.
 14. The intraocular lens ofclaim 1, wherein the chassis extends through at least a portion of eachof the paddles.
 15. The intraocular lens of claim 1, wherein the chassiscomprises a centration member.
 16. The intraocular lens of claim 1,wherein the chassis extends beyond the distal edge of the haptic body.17. The intraocular lens of claim 1, wherein the transverse memberdefines a distal boundary of the open space.
 18. The intraocular lens ofclaim 1, wherein the haptic body extends through the open space of thechassis.